Concrete form

ABSTRACT

A substantially rigid concrete form of compressed fibers is made in a substantially flat rectangular configuration. The form includes a central section and opposite side sections connected thereto by fold lines defined by rounded grooves. The side sections are foldable along the grooved fold lines relative to the central section to make a substantially U-shaped concrete form. The central section and side sections have longitudinallyspaced transverse stiffening ribs therein. At least certain of the central stiffening ribs and side stiffening ribs have end portions abutting one another when the form is folded to its substantially U-shaped configuration. This abutting relationship of the ribs supports the central section on the side sections.

United States Patent [191 Fuchs [111 3,829,057 Aug. 13, 1974 CONCRETE FORM.

[75] Inventor: LeoFuchs, Springfield, Tenn.

[73] Assignee: The mansfield Tire & Rubber Company, Mansfield, Ohio [22] Filed: Feb. 9, 1973 [21] Appl. No.: 331,102

[52] US. Cl. 249/175, 249/183 [51] Int. Cl. ..-B28b 7/28, B290 l/12 [58] Field of Search 29/D1G. 33; 52/630;

[56] I References Cited UNITED STATES PATENTS 1,056,072 3/1913 Vogan 52/630 X 2,101,019 I 12/1937 Bowes 249/18 2,160,677 5/1939 Romanoff 52/630 X 2,681,495 6/1954 Killian et al. 249/134 2,963,128 12/1960 Rapp 52/630 X 3,111,788 11/1963 Ouellet 52/630 X 3,488,027 l/197O Evans 249/134 Primary Examiner-Charles W. Lanham Assistant Examiner-E. M. Combs Attorney, Agent, or Firm-Meyer, Tilberry, & Body [5 7] ABSTRACT A substantially rigid concrete form of compressed fibers is made in a substantially flat rectangular configuration. The form includes a central section and opposite side sections connected thereto by fold lines defined by rounded grooves. The side sections are foldable along the grooved fold lines relative to the central section to make a substantially U-shaped concrete form. The central section and side sections have longitudinally-spaced transverse stiffening ribs therein. At least certain of the central stiffening ribs and side stiffening ribs have end portions abutting one another when theform is folded to its substantially U-shaped configuration. This abutting relationship of the ribs supports the central section on the side sections.

6 Claims, 7 Drawing Figures PAIENIEU mm 3 I974 SHEEI 2 0F 2 CONCRETE FORM BACKGROUND OF THE INVENTION This application pertains to the art of concrete forms and more particularly to concrete forms which can be folded to a predetermined configuration for installation. The invention is particularly applicable to use with forms made from a mixture of adhesive or synthetic plastic material and wood fibers. However, it will be appreciated that the invention can be used with forms made from other materials.

Concrete forms of a known type are commonly made from compressed wood fibers and plastic resins. Such forms for use in making concrete floors and roofs are shaped to have a substantially U-shaped cross-sectional configuration. Such forms include longitudinallyspaced transverse stiffening ribs extending across the side portions and central portion. These forms are commonly stacked or nested within one another for shipment and placement .on a construction site. The stacked forms take up a considerable amount of space and this makes shipment expensive. In addition, each successive stacked form resiliently grips the lower form. This makes separation of the stacked forms extremely difficult on a job site. In order to ease separation of such stacked forms on a construction site, spacers are commonly put between the forms. Such spacers make the shipping packages very bulky and greatly reduces the number of forms which can be hauled in a given amount of space.

Foldable concrete forms of known types include those disclosed in US. Pat. No. 2,101,019 to Bowes. In the Bowes patent, flat forms are provided with score lines so that the form may be folded into various shapes. Bowes includes one embodiment wherein the flat form is foldable along score lines into a substantially U-shaped cross-sectional configuration. However, Bowes also provides transverse score lines for folding transverse stiffening ribs into the form. The stiffening ribs are completely closed and must be held together with rivets or the like. Folding the form to pro-- videthe transverse stiffening ribs is very time consuming and substantially eliminates the advantages of the flat form. The foldable transverse stiffening ribs also require diamond-shaped openings through the form. These openings are difficult to completely close for preventing escape of concrete therethrough.

SUMMARY A concrete form of the type described includes a substantially rectangular central portion integrally connected with substantially rectangular side portions by grooves which form fold lines.

The central portion has longitudinally-spaced transverse stiffening ribs formed therein between the fold lines. The opposite side portions have longitudinallyspaced transverse side stiffening ribs therein between the fold lines and the opposite longitudinal edges of the form. The side stiffening ribs are aligned with at least certain of the central stiffening ribs.

In a preferred arrangement, the central stiffening ribs have central terminal surfaces adjacent the grooved lines. The side stiffening ribs also have side terminal surfaces adjacent the grooved lines. The side portions are foldable along the fold lines relative to the central portion. The terminal surfaces on the central and side stiffening ribs abut with one another when the form is folded into a substantially U-shaped configuration. The central portion is then supported on the side portions.

BRIEF DESCRIPTION OF THE DRAWING The invention may take form in certain parts and arrangements of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof.

FIG. 1 is a top plan view of a foldable concrete form constructed in accordance with the present invention;

FIG. 2 is a cross-sectional view looking generally in the direction of arrows 2-2 of FIG. 1;

FIG. 3 is a view similar to FIG. 2 showing the form in its folded condition;

FIG. 4 is a view similar to FIG. 3 and looking generally in the direction of arrows 44 of FIG. 1;

FIG. 5 is a partial end view looking generally in the direction of arrows 55 of FIG. 2;

FIG. 6 is a cross-sectional elevational view looking generally in the direction of arrows 66 of FIG. 1; and

vFIG. 7 is a cross-sectional elevational view looking generally in the direction of arrows 7-7 of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings, wherein the showings are for purposes of illustrating a preferred embodiment of the invention only and not for purposes of limiting same, FIG. I shows an improved concrete form A constructed in accordance with the present invention. Form A is a sheet of generally uniform thickness and has a substantially rectangular shape including substantially parallel opposite longitudinal side edges 10 and 12, and opposite transverse end edges 14 and 16.

In accordance with one arrangement, form A includes a substantially rectangular central portion B integrally connected with opposite side portions C and D by fold lines 20 and 22. Transversely spaced-apart and parallel fold lines 20 and 22 extend substantially parallel to opposite longitudinal edges 10 and 12.

In accordance with one arrangement, the outer edges of side portions C and D include upwardly and outwardly extending flanges 24 and 26. Flanges 24 and 26 extend upwardly and outwardly from side portions C and D generally along lines 28 and 30.

In accordance with one aspect of the invention, cen tral portion B includes a plurality of longitudinallyspaced transverse depressions forming integral stiffening ribs E. A plurality of smaller longitudinally-spaced transverse central stiffening ribs F are positioned intermediate stiffening ribs E in central portion B. Stiffening ribs F may be altered or eliminated in all or some areas between stiffening ribs E in other aspects of the invention. Side portions C and D include a plurality of Iongitudinally-spaced transversely extending depressions forming stiffening ribs G and H. Stiffening ribs G and H in side portions C and D are transversely aligned with stiffening ribs E in central portion B.

Central stiffening ribs E have substantially U-shaped cross-sectional configurations including spaced-apart opposite sidewalls 36 and 38 which slope downward toward one another from central portion B. Central stiffening ribs E include bottom walls 40. Central stiffening ribs F have a depth around one-half that of central stiffening ribs E. Stiffening ribs F include spacedapart opposite sidewalls 42 and 44 sloping downward toward one another from central portion B. Stiffening ribs F include bottom walls 46. Stiffening ribs E and F have substantially the same width. Ribs E and F are spaced-apart longitudinally of central portion B a distance substantially the same as the width of one stiffening rib.

Central stiffening ribs E have integral opposite end walls 48 and 50 spaced inward somewhat from fold lines and 22, and sloping toward one another at angles 54 and 55 to the vertical of around degrees.

In a preferred arrangement, central stiffening ribs E are deeper at their end portions. That is, the opposite bottom end portions of central stiffening ribs E extend downwardly below bottom wall 40. Ribs E include opposite terminal surfaces 58 and 60 which slope inward from end walls 48 and 50 at angles 62 and 64 of around 20. Thus, terminal surfaces 58 and 60 make angles 66 and 68 with the horizontal of around 45. Additional bottom end surfaces 72 and 74 slope upward from terminal surfaces 58 and 60 at angles of around 90 to intersect bottom wall 40.

Intermediate central stiffening ribs E have a substantially uniform cross-sectional configuration throughout their length and simply include opposite end walls 76 and 80 which slope toward one another from central portion B to intersect bottom wall 46 thereof.

Side stiffening ribs G and H have substantially U- shaped cross-sectional configurations including spaced-apart opposite sidewalls 86 and 88 sloping downward toward one another from side portions C and D. Side stiffening ribs G and H include bottom walls 90. Side stiffening ribs G and H have a width substantially the same as that of central stiffening ribs E. Side stiffening ribs H are spaced-apart longitudinally a distance substantially equal to around three times the width of one stiffening rib. Ribs G and H include opposite end walls 92 and 94.

Flanges 24 and 26 slope outwardly from the vertical at angles 102 and 104 of around 20. End walls 92 of side stiffening ribs H slope inwardly from flanges 24 and 26 at angles I06 and 108 of around The depth of side stiffening ribs G and H increases from end walls 92 toward end walls 94. Thus, bottom wall 90 slopes downwardly somewhat from end walls 92 toward end walls 94. In addition, ribs G and H are deeper at end portions 94 adjacent fold lines 20 and 22. Sloping surfaces 112 and 114 slope downward from bottom walls 90 at angles of around 30 to intersect end walls 94. End walls 94 slope downward and away from fold lines 20 and 22 at angles 116 and 118 to the vertical of around 25.

Form A is made from a mixture of wood fibers and resins. The mixture is inserted into a mold and from A is compressed under heat and pressure to the shape down and described. It is obvious that other materials could also be used in making form A. Fold lines 20 and 22 may be formed integrally in the mold or the form may be passed between rollers to form such fold lines 20 and 22. In the arrangement shown, form A has been passed between rollers positioned on both sides of form A. A roller on one side of form A may have a convex peripheral surface while the roller on the other side of the form has a concave peripheral surface. Thus, fold lines 20 and 22 are downwardly concave. When side portions C and D are folded downward relative to central portion B, they extend at angles 120 and 122 to the vertical in FIG. 3 of around 70. Flanges 24 and 26 extend upwardly at an angle of approximately 35 such that with side portions C and D folded downwardly through angles of around 70, flanges 24 and 26 extend substantially horizontally for resting on flanges of supporting or reinforcing beams. Also, with side portions C and D folded downwardly through angles of around 70, end walls 94 of side stiffening ribs G and H extend at angles to the horizontal of around 45 so that they abut with surfaces 58 and 60 on central stiffening ribs E and limit the angle of folding. Therefore, central stiffening ribs E are firmly supported by flat surfaces 58 and 60 on surfaces of end walls 94 on side stiffening ribs H.

This provides extremely firm support for form A in its folded condition. Additional central stiffening ribs F further reinforce central portion B against bending like a beam when concrete is placed thereover. Side stiffening ribs G and H act as columns in the folded condition of form A and provide good support for central portion B.

One end of form A may have flanges 24 and 26 stepped upwardly slightly so that adjacent end portions of the forms may overlap. This is shown only for flange 26 in FIG. 5 wherein flange 26 is stepped upwardly as at at only one end of form A. Thus, corresponding unstepped flange ends on an adjacent form may slide beneath the stepped portions 130.

Form A is molded in one integral piece to the shape shown and described. Having the forms in a substantially flat configuration makes it possible to stack a large number of the forms in a small area for shipment. The maximum use of space in a shipping vehicle is utilized. In addition, the stacked forms wedge together slightlyonly in the areas of the ribs so that they are much easier to separate'than forms which are premolded to a U-shaped configuration. In forms having a pre-molded U-shaped configuration, the opposite side portions also grip the side portions of a lower form and prevent easy separation. The substantially flat configuration of the forms also makes them easier to handle on a construction site. Workmen simply grab the forms and apply bending forces on side portions C and D which then fold along fold lines 20 and 22 until surfaces 58 and 60 on central stiffening ribs E abut surfaces 94 on side stiffening ribs G and H.

Although the invention has been shown and described with respect to a preferred embodiment, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications and is limited only by the scope of the claims.

Having thus described my invention, 1 claim:

1. A concrete form comprised of a rectangular sheet of generally rigid fiberous material of generally uniform thickness and having a plurality of depressions in the upper surface forming stiffening ribs on the lower surface thereof, said sheet having a pair of spaced parallel extending grooves forming fold lines extending in spaced parallel relationship to the side edges of said sheet dividing said sheet into a central portion and a pair of side portions which can be folded on said fold line at an angle to said central portion said central portion having a plurality of said depressions extending generally transversely thereof with the ends in close spaced relationship to said fold lines; said side portions each having a plurality of said depressions aligned with said central portion depressions and extending from a point close to said fold lines toward the side edges of said sheet; said depressions each being defined by an end wall, side walls and a .bottom, said end walls extending downwardly and outwardly away from the vertical plane through said fold line in an amount such-that when said side portions are angled downwardly from the plane of said sheet by folding said sheet on said fold lines, the adjacent end walls of said depressions of said central and side portions will abut to limit the angle of folding to a predetermined angle less than 90.

2. The form of claim 10 wherein the outer edges of said side portions are angled upwardly at an angle generally equal to said predetermined angle whereby when said side portions are folded downwardly through said 6. The form of claim 1 wherein said stiffening ribs have a greater depth adjacent said grooved lines.

l l =l 

1. A concrete form comprised of a rectangular sheet of generally rigid fiberous material of generally uniform thickness and having a plurality of depressions in the upper surface forming stiffening ribs on the lower surface thereof, said sheet having a pair of spaced parallel extending grooves forming fold lines extending in spaced parallel relationship to the side edges of said sheet dividing said sheet into a central portion and a pair of side portions which can be folded on said fold line at an angle to said central portion said central portion having a plurality of said depressions extending generally transversely thereof with the ends in close spaced relationship to said fold lines; said side portions each having a plurality of said depressions aligned with said central portion depressions and extending from a point close to said fold lines toward the side edges of said sheet; said depressions eacH being defined by an end wall, side walls and a bottom, said end walls extending downwardly and outwardly away from the vertical plane through said fold line in an amount such that when said side portions are angled downwardly from the plane of said sheet by folding said sheet on said fold lines, the adjacent end walls of said depressions of said central and side portions will abut to limit the angle of folding to a predetermined angle less than 90*.
 2. The form of claim 10 wherein the outer edges of said side portions are angled upwardly at an angle generally equal to said predetermined angle whereby when said side portions are folded downwardly through said predetermined angle said outer edges are generally coplanar.
 3. The form of claim 2 wherein said central stiffening ribs extend in spaced-apart relationship perpendicular to said fold lines and alternating ones of said central stiffening ribs have larger cross-sectional configurations than others of said central stiffening ribs.
 4. The form of claim 1 wherein said opposite side portions have upwardly extending outer flanges thereon.
 5. The form of claim 1 wherein said central portion has a greater number of said stiffening ribs than said side portions.
 6. The form of claim 1 wherein said stiffening ribs have a greater depth adjacent said grooved lines. 